1. Field of the Invention
The present invention is directed to a therapy apparatus and method for treatment of a subject with focused acoustic waves, of the type wherein a source of acoustic waves generates acoustic waves focused onto a focus and has an x-ray-transparent region, and an x-ray locating means locates a region to be treated in the subject by obtaining an image of the subject from different irradiation directions and whose central ray in at least one transillumination direction proceeds through the x-ray-transparent region of the acoustic waves source.
2. Description of the Prior Art
Therapy systems of the type generally described above serve, for example, for treating stone conditions (lithotripsy), for treating tumors or for treating bone conditions (osteorestoration). In the former instance, a shockwave source is generally provided as the source of acoustic waves. In the case of treating tumors, a pressure pulse source that generates negative pressure pulses (under-pressure) and/or an ultrasound source that emits continuous ultrasound (hyperthermia) can, for example, be provided as the source of acoustic waves. For treating bone conditions, a shockwave source is likewise normally provided as the source of acoustic waves.
For example, European Application 0 372 119 discloses a therapy apparatus of the type initially described. In this known therapy apparatus, the source of acoustic waves is connected either to the primary radiation diaphragm of the x-ray radiator or to the image intensifier of the x-ray locating means. Acoustic coupling means in the form of a flexible foil are attached to the source of acoustic waves, this coupling means being capable of application to the body surface of a subject to be treated for the purpose of acoustic coupling. For locating a region to be treated, the source of acoustic waves and the x-ray locating means must be adjusted in common relative to the subject to be treated such that irradiation of the subject with x-rays ensues from two different directions. Relative motions and forces between the body surface of the subject to be treated and the coupling means pressing thereagainst necessarily occur. Quite apart from the fact that this can be uncomfortable for the subject to be treated, i.e., a patient, it involves the risk that the subject to be treated will be displaced in an uncontrolled fashion, so that the result of the locating procedure is imprecise. It is self-evident that an exact result can only be obtained when uncontrolled dislocations of the subject to be treated are avoided between the irradiation from different directions.
German Utility Model 87 14 701 discloses a shockwave generator having a central, x-ray-transparent region, but makes no mention of irradiation of the subject to be treated ensuing from different angles with an x-ray locating means. Successive irradiation from different angles, however, is not necessary since the x-ray-transparent region is dimensioned large enough such that irradiation from different angles can simultaneously ensue through the x-ray transparent region.